target: Fail I/O with PROTECT bit when protection is unsupported

This patch adds an explicit check for WRPROTECT + RDPROTECT bit usage
within sbc_check_prot(), and fails with TCM_INVALID_CDB_FIELD if the
backend device does not have protection enabled.

Also, update sbc_check_prot() to return sense_reason_t in order to
propigate up the correct sense ASQ.

Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 32 insertions, 19 deletions

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 17259c05450e..1bb8b4a93a66 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -626,14 +626,21 @@ sbc_set_prot_op_checks(u8 protect, enum target_prot_type prot_type,
         return 0;
 }
 
-static bool
+static sense_reason_t
 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
                u32 sectors, bool is_write)
 {
         u8 protect = cdb[1] >> 5;
 
-        if ((!cmd->t_prot_sg || !cmd->t_prot_nents) && cmd->prot_pto)
-                return true;
+        if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
+                if (protect && !dev->dev_attrib.pi_prot_type) {
+                        pr_err("CDB contains protect bit, but device does not"
+                               " advertise PROTECT=1 feature bit\n");
+                        return TCM_INVALID_CDB_FIELD;
+                }
+                if (cmd->prot_pto)
+                        return TCM_NO_SENSE;
+        }
 
         switch (dev->dev_attrib.pi_prot_type) {
         case TARGET_DIF_TYPE3_PROT:
@@ -641,7 +648,7 @@ sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
                 break;
         case TARGET_DIF_TYPE2_PROT:
                 if (protect)
-                        return false;
+                        return TCM_INVALID_CDB_FIELD;
 
                 cmd->reftag_seed = cmd->t_task_lba;
                 break;
@@ -650,12 +657,12 @@ sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
                 break;
         case TARGET_DIF_TYPE0_PROT:
         default:
-                return true;
+                return TCM_NO_SENSE;
         }
 
         if (sbc_set_prot_op_checks(protect, dev->dev_attrib.pi_prot_type,
                                    is_write, cmd))
-                return false;
+                return TCM_INVALID_CDB_FIELD;
 
         cmd->prot_type = dev->dev_attrib.pi_prot_type;
         cmd->prot_length = dev->prot_length * sectors;
@@ -674,7 +681,7 @@ sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
                  cmd->prot_op, cmd->prot_checks);
 
-        return true;
+        return TCM_NO_SENSE;
 }
 
 sense_reason_t
@@ -698,8 +705,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_10(cdb);
                 cmd->t_task_lba = transport_lba_32(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
-                        return TCM_UNSUPPORTED_SCSI_OPCODE;
+                ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
+                if (ret)
+                        return ret;
 
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
                 cmd->execute_rw = ops->execute_rw;
@@ -709,8 +717,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_12(cdb);
                 cmd->t_task_lba = transport_lba_32(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
-                        return TCM_UNSUPPORTED_SCSI_OPCODE;
+                ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
+                if (ret)
+                        return ret;
 
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
                 cmd->execute_rw = ops->execute_rw;
@@ -720,8 +729,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_16(cdb);
                 cmd->t_task_lba = transport_lba_64(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
-                        return TCM_UNSUPPORTED_SCSI_OPCODE;
+                ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
+                if (ret)
+                        return ret;
 
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
                 cmd->execute_rw = ops->execute_rw;
@@ -739,8 +749,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_10(cdb);
                 cmd->t_task_lba = transport_lba_32(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
-                        return TCM_UNSUPPORTED_SCSI_OPCODE;
+                ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
+                if (ret)
+                        return ret;
 
                 if (cdb[1] & 0x8)
                         cmd->se_cmd_flags |= SCF_FUA;
@@ -752,8 +763,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_12(cdb);
                 cmd->t_task_lba = transport_lba_32(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
-                        return TCM_UNSUPPORTED_SCSI_OPCODE;
+                ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
+                if (ret)
+                        return ret;
 
                 if (cdb[1] & 0x8)
                         cmd->se_cmd_flags |= SCF_FUA;
@@ -765,8 +777,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_16(cdb);
                 cmd->t_task_lba = transport_lba_64(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
-                        return TCM_UNSUPPORTED_SCSI_OPCODE;
+                ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
+                if (ret)
+                        return ret;
 
                 if (cdb[1] & 0x8)
                         cmd->se_cmd_flags |= SCF_FUA;